Weinan Xing

Non-integer induced spontaneous polarization of highly efficient perovskite-based NBTO SCN photocatalysts

Perovskite oxides and their derivative photocatalysts are promising candidates for highly efficient solar energy conversion and environmental remediation. Herein, we proposed a non-integer induced spontaneous polarization of highly efficient perovskite-based NBTO SCN photocatalysts. The experimental and theoretical results demonstrate that the Na0.5Bi2.5Ta2O9 single-crystal nanoplates (NBTO SCNs) with exposed {001} facets show more superior photocatalytic efficiency in hydrogen evolution and pollutant degradation than conventional integer NaTaO3 and BiTaO4. The non-integer structure (mixed A-site cations Na+ or Bi3+) of NBTO SCNs possesses giant spontaneous polarization along the c-axis. Therefore, the generated carriers can easily diffuse along the polarization direction to the opposite surfaces of catalysts, and thus significantly increase the photocatalytic activities of NBTO SCNs.

Biocoordination Polymer Cross-Linking Structure to a 3D Star Topology Inorganic Photocatalyst Nanocrystal with Improved Hydrogen Evolution Performance

An inorganic photocatalyst with a novel 3D star topology (ST) framework was obtained via multiple cross-linking of biocoordination polymers in one-step solvothermal conditions. It possessesd a large surface area (149.36 m2·g-1), among the highest value of the current reports, and represented the quantum size effect because of its 3D ST structure. The amino acid l-cysteine was introduced into the synthesis system to lead generation of the biometic coordination polymer through the amino acid dehydrate condensation and multiple cross-linking.

Anchoring Active Pt2+/Pt0 Hybrid Nanodots on g-C3N4 Nitrogen Vacancies for Photocatalytic H2 Evolution

A Pt2+ /Pt0 hybrid nanodot-modified graphitic carbon nitride (CN) photocatalyst (CNV-P) was fabricated for the first time using a chemical reduction method, during which nitrogen vacancies in g-C3 N4 assist to stabilize Pt2+ species. It is elucidated that the coexistence of metallic Pt0 and Pt2+ species in the Pt nanodots loaded on g-C3 N4 results in superior photocatalytic H2 evolution performance with very low Pt loadings. The turnover frequencies (TOFs) are 265.91 and 116.38 h-1 for CNV-P-0.1 (0.1 wt % Pt) and CNV-P-0.5 (0.5 wt % Pt), respectively, which are much higher than for other g-C3 N4 -based photocatalysts with Pt co-catalyst reported previously. The excellent photocatalytic H2 evolution performance is a result of i) metallic Pt0 facilitating the electron transport and separation and Pt2+ species preventing the undesirable H2 backward reaction, ii) the strong interfacial contact between Pt2+ /Pt0 hybrid nanodots and nitrogen vacancies of CNV facilitating the interfacial electron transfer, and iii) the highly dispersed Pt2+ /Pt0 hybrid nanodots exposing more active sites for photocatalytic H2 evolution. Our findings are useful for the design of highly active semiconductor-based photocatalysts with extremely low precious metal content to reduce the catalyst cost while achieving good activity.